Missile altitude sensing system

ABSTRACT

A non-rotating sphere is floated on a spherical air film. Provision is made for a double pneumatic integration of the vertical component of acceleration to indicate the desired missile arming altitude. A control output signal is then generated at the predetermined altitude and used to arm the missile or otherwise control it in its operation.

United States Patent [191 McKenney [4 1 Feb. 25, 1975 MISSILE ALTITUDESENSING SYSTEM Henry F. McKenney, Bloomfield Hills, Mich.

Assignee: Chrysler Corporation, Highland Park, Mich.

Filed: Mar. 25, 1969 Appl. No.: 810,389

Inventor:

US. Cl. 73/490, 73/503 Int. Cl GOlc 21/16 Field of Search 102/702, 81;73/490, 503,

References Cited UNITED STATES PATENTS 2,958,279 11/1960 Haberland102/81 X 3,080,761 3/1963 Speen 73/516 3,276,270 10/1966 Speen 3,302,4662/1967 Ogren 73/516 Primary Examiner-Verlin R. Pendegrass Attorney,Agent, or Firm-Talburtt & Baldwin [57] ABSTRACT A non-rotating sphere isfloated on a spherical air film. Provision is made for a doublepneumatic integration of the vertical component of acceleration toindicate the desired missile arming altitude. A control output signal isthen generated at the predetermined altitude and used to arm the missileor otherwise control it in its operation.

6 Claims, 2 Drawing Figures MISSILE ALTITUDE SENSING SYSTEM BACKGROUNDOF THE INVENTION The field to which my invention relates is that ofmissiles operating in a boost phase mode. The initial launchingdirection is vertical with ground commanded flight direction. Myaltitude sensing system meets the requirements of simple and reliableconstruction, long shelf life, freedom from necessity for pre-flightcheckout and operation in a severe environment. The system incorporatesa floating sphere thus allowing only vertical acceleration to be sensedindependently of the missile attitude or position.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a vertical half-sectionalview of my invention with parts shown in partial diagrammatic form toclarify its operation; and

FIG. 2 shows an alternate embodiment of the arming device of inventionas incorporated in the basic struc ture of FIG. 1.

DESCRIPTION FIG. 1 shows the detail of construction of my pneumaticallysuspended integrated altitude sensing device. An outer shell hasconnected to it a high pressure regulated source 12. Air flow isprovided through manifold 14 as indicated by the arrows. Upper and lowercaging pins 16, 18, are released by the flow of air from pressure source12. The detail ofa suitable cage release mechanism is shown inconnection with upper caging pin 16. The inrush of pressurized airdeflects diaphragm to its upper dash line position to move pin 16upwardly thus permitting the inner spherical elements of the device tofloat freely on a layer of pressurized air. This supporting-air layer orfilm is denoted by the numeral 22. A uniform distribution of pressurizedair is passed from manifold 14 to layer 22 through a porous or randomlyperforated shell 24.

The floating elements include outer spherical shell 26 and innerspherical shell 28. These two shells define between them top and bottomfirst chambers 30a and 30b. Inner shell 28 further is divided into upperand lower chambers 32a and 32b. Upon the release of caging pins 16 and18,. integrating orifices 34a, 34b are opened to permit passage of airtherethrough. Under acceleration, the inertial mass of shells 26 and 28which are supported on the pressurized air film deflects. Thisdeflection causes the metering of the flow of air differently throughupper and lower orifices 34a and 34b. The differential pressurebuild upbetween chambers 34a, 34b represents the first integral of accelerationwith respect to time i.e., velocity. Additionally, in the flow of airthrough the second set of orifices 36a, 3612, a second integrationprocess is performed. A differential pressure transducer38 is shownmounted between chambers 32a and 32b. This transducer may be embodiedfor example as a squib which is actuated when the differential pressurereaches a predetermined magnitude. This will serve to provide a controlsignal output which is utilized in a manner well known in the art to armthe missile warhead or otherwise exercise control over the missile. Togenerate this signal, a pick-up 40 may be employed in the system tosense the seismic shock of the squib and respond thereto.

FIG. 2 is a schematic showing of an alternate embodiment of my inventionin which a different type of transducer is used to generate a controloutput signal suitable to arm the missile. In this form of my invention,the triggering may be accomplished by a toggle'action device or oil cantype trigger as is shown. The upper and lower diaphragms 41a, 4lb aredeflectable to their respective dashed line positions to detonate asquib 42 through firing pin 43. Responsive: to the firing of squib 42apair of plungers 44, 45 are driven in opposite directions. Porous shell24 in this case is formed in an upper and a lower hemisphere, eachelectrically insulated from the other by an insulating ring 46 of thecrosssectional configuration shown. lPlungers 44, 45 thus serve to shortthe insulated upper and lower halves together and provide an electricaloutput signal for arming the missile warhead.

DESCRIPTION OF OPERATION The missile is provided with a launch forcealong its thrust axis as designated by the arrow A of FIG. 1. Concurrentwith the firing of the missile, the air from high pressure source 12 isreleased through outer manifold 14 to uncage pins 16 and 18 which pinsextend through porous shell 24 to maintain a layer or film 22 ofpressurized air. Shell 24 has the ability of maintaining a definitiveorientation since it is non-rotating and is supported by a virtuallyfrictionless air film to minimize drag. Because of the spherical shapeof shell 26, it allows up to 360 of freedom of missile movement (aboutthree axes) without adversely affecting the basic sensor function. Forthe shell 24 to be supported, it is necessary for the static pressure onthe lower hemisphere to average higher than that on the upperhemisphere. In the undeflected condition, the air flow is along themeridian, separating at the equator toward orifice 34a in a northerlyorientation and toward orifice 34b in a southerly orientation.

When an axial deflection occurs at launch, the flow is still along themeridian but with a wider gap between the upper hemisphere of shell 26and porous shell 24 than between the lower hemisphere of shell 26 andporous shell 24. Accordingly, a greater flow volume will reach upperorifice 34a than lower orifice 3412. As the lower gap closes down underthe loading, the static pressure rises approaching a significantfraction of the pressure of outer manifold 14 while the velocity becomesrelatively slow. The dividing line of the northerly and southerlyportions of the flow field will move to the southern latitudes so thatupper orifice 34a will be supplied by air influxing over a larger areaof porous shell 24. Over the region where the deflection of the flowdividing line is proportioned to g loading, the differential flow intofirst chambers 30a, 30b will also be proportional to g loading. If theflow through upper and lower orifices 34a, 34b is essentiallyindependent of downstream pressure, the differential pressure ofchambers 30a, 30b will represent missile vertical velocity. If orifices36a, 36b admitting air to second chambers 32a, 32b are made smallenough, we have the required condition that flow is essentiallyindependent of downstream pressure. The differential pressure betweenthe second chambers 32a, 32b provides a good representation of theinertial displacement of the missile in the vertical direction. Whenthis differential pressure reaches a predetermined magnitude, thetransducer 38 of FIG. I will provide an output signal from pickup 40responsive to firing of a squib. in the modification of FIG. 2, theupper and lower insulated sections of shell 24 are shorted togetherresponsive to the firing of squib 42 and the operation of plungers 44,45.

It will be appreciated that in some cases the volume of air required forflotation of the shells will be too large to be accommodated in theintegration chambers without using excessive pressure. The structurewill then be modified to provide that only a portion of the flotationair in layer 22 will be passed to the integrating orifices. Theremainder will be exhausted externally through small distributedorifices back through perforated shell 24 to an exhaust manifold. Theintegrating orifices would be multiple in order to average out theeffect of individual input and exhaust openings.

I claim:

1. An altitude sensing system for a missile during its boost phasecomprising a spherical shell, a hydrostatic perforated bearing structureenclosing said shell, a gas pressure source for providing high pressureflow through said bearing structure to support said shell on apressurized gas film, a first integrating chamber of said shell, asecond integrating chamber of said shell formed interior of said firstchamber, a first pair of integrating orifices formed in said firstchamber along the longitudinal axis of said missile, one at the upperand the other at the lower end of said first chamber, said first pair oforifices communicating between said gas film and the interior of saidfirst air chamber, a second pair of integrating orifices aligned alongsaid axis at opposite ends of said second chamber, said second pair oforifices communicating between said second chamber and said firstchamber, respectively, and a differential pressure sensing means mountedin said second chamber for providing a control output signal responsiveto a pressure differential representative of predetermined missiledisplacement.

2. The combination as set forth in claim 1 wherein said shell comprisesa porous structure of two hemispheric parts each electrically insulatedfrom the other and a firing device is connected to said differentialpressure sensing means for shorting said parts together and providing anelectrical output signal.

3. The combination as set forth in claim 1 wherein a seismic shockresponsive device is operating connected to and responsive to saidfiring device for providing said control output signal.

4. An altitude sensing system for a missile during its boost phasecomprising a spherical shell, a hydrostatic bearing structure of porousmaterial enclosing said shell, a gas pressure source connectible to saidbearing structure for providing a high pressure gas flow through saidbearing structure to support said shell on a pressurized gas film, anexhaust manifold connected to a plurality of return conduits formed insaid bearing structure to exhaust a portion of said gas, a firstintegrating chamber formed in said shell, a second integrating chamberformed in said shell and enclosed by said first chamber, a north and asouth polar orifice formed in each of said chambers, said orifices lyingalong the missile thrust axis, and a differential pressure sensing meansmounted within said second chamber and responsive to a differential inpressure existing between its two ends to provide a control outputsignal representative of a predetermined magnitude of missile dis,-placement.

5. A displacement responsive system for an object movable in a linearpath comprising a spherical shell, a hydrostatic bearing structurecontaining said shell, a gas pressure source connectable at a number ofpoints to said bearing structure for providing a high pressure flowtherethrough for supporting said shell on a pressurized gas film, asecond spherical shell mounted in said first spherical shell andconcentric therewith, planar means passing through both of said shellsat their centers normal to said path to divide each into substantiallyequal hemispheric portions, each of said portions having an upper and alower orifice lying along said path, a differential pressure sensingmeans mounted in said second shell between its two hemispheric portionsand operable to provide an output signal responsive to the movement ofsaid object over a predetermined distance. i

6. A displacement responsive system for an object movable in a linearpath comprising a first spherical shell, a hydrostatic bearing structurecontaining said shell, a gas pressure source connectible at a pluralityof points to said bearing structure for providing a high pressure flowtherethrough for supporting said first shell on a pressurized gas film,a second spherical shell mounted in said first spherical shell,concentric therewith and spaced therefrom, each of said shells having anupper and a lower integrating orifice, said orifices lying along saidpath, and a differential pressure means mounted in said second sphericalshell and responsive to a predetermined magnitude of the differentialpressure to provide an output signal representative of distancetraveled.

1. An altitude sensing system for a missile during its boost phasecomprising a spherical shell, a hydrostatic perforated bearing structureenclosing said shell, a gas pressure source for providing high pressureflow through said bearing structure to support said shell on apressurized gas film, a first integrating chamber of said shell, asecond integrating chamber of said shell formed interior of said firstchamber, a first pair of integrating orifices formed in said firstchamber along the longitudinal axis of said missile, one at the upperand the other at the lower end of said first chamber, said first pair oforifices communicating between said gas film and the interior of saidfirst air chamber, a second pair of integrating orifices aligned alongsaid axis at opposite ends of said second chamber, said second pair oforifices communicating between said second chamber and said firstchamber, respectively, and a differential pressure sensing means mountedin said second chamber for providing a control output signal responsiveto a pressure differential representative of predetermined missiledisplacement.
 2. The combination as set forth in claim 1 wherein saidshell comprises a porous structure of two hemispheric parts eachelectrically insulated from the other and a firing device is connectedto said differential pressure sensing means for shorting said partstogether and providing an electrical output signal.
 3. The combinationas set forth in claim 1 wherein a seismic shock responsive device isoperating connected to and responsive to said firing device forproviding said control output signal.
 4. An altitude sensing system fora missile during its boost phase comprising a spherical shell, ahydrostatic bearing structure of porous material enclosing said shell, agas pressure source connectible to said bearing structure for providinga high pressure gas flow through said bearing structure to support saidshell on a pressurized gas film, an exhaust manifold connected to aplurality of return conduits formed in said bearing structure to exhausta portion of said gas, a first integrating chamber formed in said shell,a second integrating chamber formed in said shell and enclosed by saidfirst chamber, a north and a south polar orifice formed in each of saidchambers, said orifices lying along the missile thrust axis, and adifferential pressure sensing means mounted within said second chamberand responsive to a differential in pressure existing between its twoends to provide a control output signal representative of apredetermined magnitude of missile displacement.
 5. A displacementresponsive system for an object movable in a linear path comprising aspherical shell, a hydrostatic bearing structure containing said shell,a gas pressure source connectable at a number of points to said bearingstructure for providing a high pressure flow therethrough for supportingsaid shell on a pressurized gas film, a second spherical shell mountedin said first spherical shell and concentric therewith, planar meanspassing through both of said shells at their centers normal to said pathto divide each into substantially equal hemispheric portions, each ofsaid portions having an upper and a lower orifice lying along said path,a differential pressure sensing means mounted in said second shellbetween its two hemispheric portions and operable to provide an outputsignal responsive to the movement of said object over a predeterMineddistance.
 6. A displacement responsive system for an object movable in alinear path comprising a first spherical shell, a hydrostatic bearingstructure containing said shell, a gas pressure source connectible at aplurality of points to said bearing structure for providing a highpressure flow therethrough for supporting said first shell on apressurized gas film, a second spherical shell mounted in said firstspherical shell, concentric therewith and spaced therefrom, each of saidshells having an upper and a lower integrating orifice, said orificeslying along said path, and a differential pressure means mounted in saidsecond spherical shell and responsive to a predetermined magnitude ofthe differential pressure to provide an output signal representative ofdistance traveled.